Was bored and decided to create a spreadsheet about gold units. Figured out the average gold cost per attack and defense stat for crate units and non-crate units. Then compared the average costs of the two. On average you should be getting over double your gold's worth opening crates, as opposed to just buying the non-crate units. This was already common knowledge, but just wanted to see the numbers.
On average, you should be receiving a unit from the crates with an attack of 49.05 and defense of 50.42 (using the following equations with current WWII crates):
[ ( 0.65 * ( (14+25+29) / 3) )+( 0.25 * ( (72+85+62)/3) ) )+(0.1 * ( (126+145+211)/3) ) ] = 49.05
[ ( 0.65 * ( (26+38+21)/3) )+( 0.25 * ( (87+74+59)/3) ) )+(0.1 * ( (195+119+96)/3) ) ] = 50.4167
This averages out to 0.985 gold spent per attack stat and 0.9586 spent per defense stat (Assuming you buy a 3 pack which is 48.33 gold per crate). When this is compared to non-crate units (2.47 gold spent per attack and 2.61 per defense) you are getting just over 2.5 times the value.
Attack: (2.47/.985) = 2.51
Defense: (2.61/.9586) = 2.72
Like I said, was just bored haha.